Elemental tungsten, tungsten–nickel alloys and shotgun ammunition: resolving issues of their relative toxicity

Abstract

Failure to distinguish between elemental tungsten and tungsten alloys has caused confusion, especially about their relative toxicity in shotgun ammunition. Controlled experiments indicate that the carcinogenicity of embedded tungsten–nickel–cobalt alloys derives from their nickel and cobalt content, and not the tungsten. The carcinogenicity of metallic nickel and cobalt implants in animal tissues is well-established. Studies in which pure tungsten metal is embedded in animal and human tissues indicate that there is no toxicity or carcinogenicity developed locally or systemically. The exposed tungsten corrodes slowly in the tissue fluids and is excreted from the body. Chronic studies in which pure tungsten-based shot are placed, continuously, in the foregut of ducks over 150 days indicate that there are no adverse physiological effects, nor disruption of ducks’ reproduction and development of their progeny. This type of shot is environmentally safe and non-toxic to animals. Shot containing nickel could pose health problems to animals if embedded in their tissues. The use of known toxic metals in lead-free shot should be subjected to further examination and, if warranted, regulation.